WASHINGTON — President Barack Obama sought to bring comfort to the people of Newtown and across the country Sunday night, speaking at a vigil to honor the 27 lives lost in Friday's shooting, but also called for national soul-searching — and action — to prevent future massacres.

"We as a nation are left with some hard questions," Obama said in a somber speech at Newtown High School after meeting with the families of the dead and the first responders who rushed to the scene of the carnage.

"We can't tolerate this anymore," he said, traveling for the fourth time of his presidency to a community torn by gunfire, but also referencing smaller acts of violence in cities and towns across the country. "These tragedies must end. And to end them, we must change."

And the fourth time, Obama's lofty rhetoric gave way to a determined call for change. Stating that every generation is judged by how well it cares for the ones following it, Obama gave his brutal assessment that the country is failing to keep its children safe.

“If we’re honest with ourselves, the answer is no," he said. "We’re not doing enough, and we’ll have to change.”

"What choice do we have?" Obama added, visibly steeling himself as he faced the families. "Are we really prepared to say that we're powerless in the face of such carnage, that the politics are too hard?"

On Friday, speaking through tears and pausing to compose himself, Obama called for "meaningful action" after the shooting, and many in his party and across the country called for the immediate proposal of legislation to strengthen gun control. Obama didn't specify what steps he will take Sunday, but forcefully said he will “use whatever power this office hold to engage my fellow citizens…to prevent tragedies like this.”

"Are we prepared to say that such violence visited upon our children year after year after year is somehow the price of our freedom," Obama asked, in a sign that he will take up such legislation, even without mentioning the word "gun" in his speech. "No single law or set of laws can eliminate evil from the world," he added, "...but that can't be an excuse for inaction."

Closing his remarks after reading the first names of the 20 first graders who were shot dead, Obama called for the nation to come together — to stop acts of violence.

"Let us find the strength to carry on and to make our country worthy of their memory," he said, as sobs echoed through the auditorium.